Mohamad Ikram Ashaari and his four wives and children at his home in Kuala Lumpur. Palani Mohan for International Herald Tributne.

KUALA LUMPUR â€” Rohaya Mohamad, 44, is an articulate, bespectacled medical doctor who studied at a university in Wales. Juhaidah Yusof, 41, is a shy Islamic studies teacher and mother of eight. Kartini Maarof, 41, is a divorce lawyer and Rubaizah Rejab, a youthful-looking 30-year-old woman, teaches Arabic at a private college.

The lives of these four women are closely entwined â€” they take care of each othersâ€™ children, cook for each other and share a home on weekends.

They also share a husband.

The man at the center of this matrimonial arrangement is Mohamad Ikram Ashaari, the 43-year-old stepson of Hatijah Aam, 54, a Malaysian woman who in August established a club to promote polygamy.

â€œMen are by nature polygamous,â€ said Dr. Rohaya, Mr. Ikramâ€™s third wife, flanked by the other three women and Mr. Ikram for an interview on a recent morning. The women were dressed in ankle-length skirts, their hair covered by tudungs, the Malaysian term for headscarf. â€œWe hear of many men having the â€˜other woman,â€™ affairs and prostitution because for men, one woman is not enough. Polygamy is a way to overcome social ills such as this.â€

The Ikhwan Polygamy Club is managed by Global Ikhwan, a company whose businesses include bread and noodle factories, a chicken-processing plant, pharmacies, cafes and supermarkets. Mr. Ikram is a director of the company.

While polygamy is legal in predominantly Muslim Malaysia, the club has come under fire from the government and religious leaders, who suspect it may be an attempt to revive Al-Arqam, a defunct Islamic movement headed by Mrs. Hatijahâ€™s husband, Mr. Ashaari Mohamad, who is the founder and owner of Global Ikhwan. Al-Arqam was banned in 1994 for â€œdeviantâ€ religious teachings.

The club denies allegations that it is trying to revive Al-Arqam, and says that the aim of the club is to help single mothers and women past â€œmarrying ageâ€ find husbands.

The Ikhwan Polygamy Club says it has 1,000 members across Malaysia, Indonesia, Australia, Singapore, Thailand, the Middle East and Europe. It recently started a branch in Bandung, Indonesia, and plans to open another one in Jakarta. Most of the members are employees of Global Ikwan or former members of Al-Arqam.

Members get together regularly for meetings and relationship counseling, which is given by senior members of the group.

Under Malaysian law, it is legal for Muslim men to marry as many as four wives, although they must obtain permission from an Islamic, or shariah, court to marry more than one. Womenâ€™s groups say it has become easier for men to obtain permission to take multiple wives in recent years, a development they say coincides with a rise in Islamic conservatism in Malaysia.

While some states require men to obtain the consent of their existing wives before seeking court permission to marry another wife, Saâ€™adiah Din, a family lawyer who practices in the shariah courts, said other states no longer required the wivesâ€™ consent.

In 2008, 1,791 men applied to the shariah courts, which apply only to the countryâ€™s Muslim population, for permission to take another wife, up from 1,694 in 2007. The government could not provide figures on the total number of polygamous marriages, but researchers including Norani Othman, a sociologist at the National University of Malaysia, said the number could be as high as 5 percent of all marriages. Despite the growing number of polygamous marriages, the clubâ€™s effort to promote the practice has put it in the sights of the authorities.

The Department of Islamic Development Malaysia, a government department that is responsible for the promotion and administration of Islam, is investigating the activities of the Ikhwan Polygamy Club and says it believes Mr. Ashaari and his family may be promoting teachings contrary to Islam. A spokeswoman would not provide further details, saying the investigation was continuing.

Al-Arqam had asserted that Mr. Ashaari had the power to forgive the sins of Muslims, an act Muslims believe can be done only by God. Some reports have suggested that the movement had as many as 10,000 members when it was banned.

A leading religious official, Harussani Bin Haji Zakaria, the mufti of Perak State, said followers of Al-Arqam had claimed that Mr. Ashaari had the power to send people to heaven or hell.

Mr. Harussani said he believed the polygamy club could be a front to resurrect Al-Arqam. â€œI think because they have been banned they want to attract people to come to him again,â€ he said, referring to Mr. Ashaari.

The club has also been criticized by womenâ€™s groups like Sisters in Islam, a nongovernmental organization based in Malaysia.

Ms. Norani, the sociologist, who is the lead researcher in a Sisters in Islam project investigating polygamy, said the practice could be harmful to women and children, particularly those born to first wives.

She and her fellow researchers have interviewed 2,000 men, women and adult children who have experienced polygamous marriage.

Although she stressed that her comments were based on preliminary observations, Ms. Norani said many of the first wives interviewed reported feelings of resentment and depression after their husbands took a second wife, and â€œa significant numberâ€ had considered divorce.

She said she knew some well-educated, financially independent women in Kuala Lumpur, including business executives and lawyers, who had chosen to become second or third wives.

â€œUsually they marry late, they do a second or third degree, they put off marriage until later and they find it difficult to find an unmarried man,â€ she said. â€œOne of them said â€˜all the good men are either married or gay.â€â€™

With 17 children among them, ages 6 to 21, Mr. Ikramâ€™s four wives all have their own homes near their workplaces, but on weekends they gather at the familyâ€™s five-bedroom house on the outskirts of Kuala Lumpur.

Most of the older children are at boarding school or university, but the children of primary-school age stay at the family house, where they are usually cared for by the first wife, Juhaidah, during the week.

Mr. Ikram takes turns spending nights with each of his four wives. â€œItâ€™s like one, two, three, four,â€ said Dr. Rohaya, pointing to each of the wives.

The wives usually meet Mr. Ikram at the family house but they say there is no strict arrangement, and Mr. Ikram sometimes comes to their individual homes during the week.

On weekends, at the family house, the women take turns doing the cooking.

None of the women grew up in polygamous families, and although they admit to having had some initial reservations, they all said they were happy and would recommend polygamous marriage to their daughters.

Mr. Ikram rejected suggestions from the womenâ€™s groups that polygamous marriages may benefit men while causing hardship for women.

â€œActually, in a polygamous marriage itâ€™s more of a burden to a man than to a woman because the husband has to face four different women, and thatâ€™s not easy,â€ he said, prompting laughter from his wives.